Ok, I figued out how to insert the gurts on the walls, but if you look back at the picture, there are also beams at the top of the wall, connecting to the roof ridge line, of which I'm not sure on how to create that either. Can I take a beam, and create the roof ridge with the beam? And my other question is, how can I insert tilted beams (for support of the slope on the roofing) from the tops of the beams on the wall to connect to the roof ridge?

Those roof ridge beams we call purlins. Yes you can go into properies and tilt them to the desired angle of the roof. What you need to do is take a specific item in EV and play a bit with it. That is how we all learned. Yes you can ask a lot of questions, and you'll get a lot of answers, but all of us are working full time and can not give you a full time training on EV.